My next slip neighbor was set to take off sailing about the world
today for the rest of his & her lifes. They have a P40 that they
tricked out. 6 mo. ago they were struck by lightning. He re-wired the
whole boat, all the wires were melted on the boat. Well last thursday
he pulled his boat to rise the water line due to all the extra gear
they installed. To everyones horror his 3 month old shaft and prop
were eaten by electrolysis, and I mean eaten up, the prop looked like
a noodle strainer and the shaft was over half eaten away. My zincs
took a beating, I jumped in the Ice tea temp water yeaterday to check
out my underside hull. My zincs were approx 30-50% gone.

My guess is that he missed wired a DC ground on his boat.

Question is: Will his screw up eat his boat totally up before it
drifts to others here in the marina because electricity seeks the
shortest path of least resistance, or is it just as likely he ate up
other shafts here in the marina.

I metered the water on all the boat slips and it seems with him gone
most of the slips measure .21 VDC. Is this voltage due to the metal
leads of the meter in the salt water, or is it perhaps due to
something else charging the water like a nicked telephone line ect.

One of the guys here went to west marine and bought a Galvanic
preventer, and when he wired it up he had 4.8 DC volts in the water at
his slip. He said the stupid F**Ks at the factory most likely put the
diodes in backwards and took it back. Perhaps my slip neighbors put
the same defective preventer on their boat.

Is there any type of permanent meter I can install on my boat that
will show electrolysis activity in the water?

And with half my zincs still in place would you recommend pulling the
boat and shaft just incase? This will cost me 300+ dollars, and if I
haul I will go ahead and do a bottom job a year or 2 ahead of
schedule, this will cost me another 1,500 dollars.

Lesson learned: If anyone in your marina is doing electrical work on
their boat, grab your volt meter and meter from his plug-in ground and
drop a lead in the water next to his boat and check for DC current
every night until he is finished !!!!!!!!!!!

Joe
MSV RedCloud